Instructional videos from a coach development workshop including 2 part Bruce Elliott & M. Reid video on the forehand. The first part is 56 minutes long and the first minutes are about foot work. Most stroke swing information starts at about 30 minutes.

16) When viewing PubMed.gov abstracts of many publications may be available free. To view the free paper look for an icon in the upper right side of the webpage with the abstract. Usually indicates 'view free text' somewhere but that phrase is not a link. For example, http://www.ncbi.nlm.nih.gov/pubmed/17513331 show abstract and link for paper #12.

(I thought that an ISBS biomechanics conference in July 2012 was to have a session on tennis and a special ITF tennis publication. But just learned that there’s no special session on tennis and, I guess ?, no special issue on the latest tennis research.)

Just received reference Technique Development in Tennis Stroke Production

This afternoon I received the IFT book Technique Development in Tennis Stroke Production(2009), B. Elliott, M. Reid and M. Crespo

Suppliers Amazon, Barnes & Noble, etc. all list it as ‘out of stock’. No wonder I had not heard of this 2009 biomechanics book on tennis stroke techniques. I found it for sale at the ITF Store. $20 + $8 shipping. (ITF, get some book retailers!)

I may have misunderstood this picture of new research related to the stretch-shortening cycle on the microscopic scale.

The Hill Muscle Model shows the functional components of a muscle on the smallest scale. It provides a way to visualize what is going on and to think about how active muscle components (actin & myosin) and passive muscle stretch component (recently also the Titin protein molecule) might function.

Recently, new research has emphasized the role played by passive Titin, the largest protein molecule, also located within the sacomere in parallel with the active Actin and Myosin structures. Recently it has been considered that Titin in each muscle cell provides the main stretch capability of the muscle. An older theory views stretch as an overall muscle stretch to include tendons.

I don't understand this last research but maybe it implies that a stretch can be deliberately activated at various lengths of the muscle.

This new research might be especially important along with other research that indicates muscle shortening might be faster if 'passive' stretch is employed instead of active muscle shortening. (the Actin -Myosin animation above even looks slow).

In Biomechanics of Advanced Tennis (2003). Elliott said

"10-20% of additional racket head speed is achieved following a stretch shortening cycle."

(This publication is now 10 years old so there may be different views in 2013.)

Is that a simple addition to racket head speed or is passive stretch derived muscle shortening the only mode that can shorten that fast with control and reproducibility? Main principle of athletic movement?

When a muscle is actively stretched (shortened) its steady-state force following the stretch (shortening) is increased (decreased) relative to the purely isometric force at the same length. This history dependence of muscle force production was first described systematically more than half a century ago (1), but cannot be explained by the reigning paradigm of muscle contraction: the cross-bridge theory (2, 3). For the past three decades, history dependence had been explained with structural non-uniformities; specifically the development of sarcomere length non-uniformities when muscles were stretched (shortened) actively on the “unstable” descending limb of the force-length relationship (4, 5). The sarcomere length non-uniformity theory allowed for precise predictions, including that force enhancement following an active stretch cannot occur on the ascending part of the force-length relationship and that the enhanced forces can never exceed the maximal isometric forces at obtained on the plateau of the force-length relationship. However, these two basic predictions were shown to be not satisfied in a series of experiments from different laboratories (e.g. 1, 6). Recently, we discovered that passive forces following an active stretch of muscles, fibres and myofibrils were increased (7). When eliminating titin from isolated myofibril preparations, this passive force enhancement was abolished indicating that titin might play a force regulatory role. Stretching troponin C depleted myofibrils (to inhibit cross-bridge connections between the contractile proteins actin and myosin) in solutions of increasing calcium concentration resulted in an increase in passive forces, suggesting that titin is a molecular spring whose stiffness can be modulated by calcium (e.g., 7). Unfortunately, the increase in force associated with titin’s calcium sensitivity only accounted for a few percent of the observed increases in passive force with active muscle stretching. When stretching single myofibrils passively (low calcium concentration) and actively (high calcium concentration) beyond actin-myosin filament overlap, forces in the actively stretched condition were 3-4 times greater at lengths where cross-bridge forces were absent, and these differences reached values approximately 2-3 times the maximum active isometric force at the plateau of the force-length relationship. How can such high forces be explained in the absence of actin-myosin based cross-bridges forces? When eliminating titin, these force difference are abolished. Calcium activation alone (when cross-bridge attachments are inhibited) merely accounts for a tiny amount of the observed force increases. However, when myofibrils are actively stretched from different parts of the descending limb of the force-length relationship, and thus from different force levels, the increase in force beyond actin-myosin filament overlap is proportional to that force (Figure 1). From these results we conclude that titin is a strong regulator of force in skeletal muscle and becomes particularly important at long sarcomere lengths. Titin’s force regulation depends on the amount of active force, but is essentially independent of calcium concentration. We tentatively suggest that titin’s force regulation is caused by a force-dependent interaction of titin with actin which causes the free spring length of titin to become smaller thereby increasing its stiffness, and thus force upon stretching.

ABSTRACT The sliding filament theory of muscle contraction is widely accepted as the means by which muscles generate force during activation. Within the constraints of this theory, isometric, steady-state force produced during muscle activation is proportional to the amount of filament overlap. Previous studies from our laboratory demonstrated enhanced titin-based force in myofibrils that were actively stretched to lengths which exceeded filament overlap. This observation cannot be explained by the sliding filament theory. The aim of the present study was to further investigate the enhanced state of titin during active stretch. Specifically, we confirm that this enhanced state of force is observed in a mouse model and quantify the contribution of calcium to this force. Titin-based force was increased by up to four times that of passive force during active stretch of isolated myofibrils. Enhanced titin-based force has now been demonstrated in two distinct animal models, suggesting that modulation of titin-based force during active stretch is an inherent property of skeletal muscle. Our results also demonstrated that 15% of titin's enhanced state can be attributed to direct calcium effects on the protein, presumably a stiffening of the protein upon calcium binding to the E-rich region of the PEVK segment and selected Ig domain segments. We suggest that the remaining unexplained 85% of this extra force results from titin binding to the thin filament. With this enhanced force confirmed in the mouse model, future studies will aim to elucidate the proposed titin-thin filament interaction in actively stretched sarcomeres.

Players of all ages appear to prepare their bodies and generate racquet velocity similarly in both
successful and unsuccessful serves. The similarity in discrete body kinematics suggests that service
faults cannot be attributed to a single source of mechanical error. However, service faults are characterized
by projection angles significantly further below the horizontal, suggesting that this parameter
is a determinant of serve outcome. Similar to other dexterous skills, compensatory variability in the
distal (elbow and wrist) joints immediately prior to impact appears critical to the regulation of projection
angle, as it allows players to adjust to the variable impact location. Given that the impact location
cannot be predetermined, perceptual feedback may play an important role in the compensation
process. For this reason, coordination of the distal degrees of freedom and a refined perception-action
coupling appear more important to success than any single kinematic component of the service action.
With this in mind, the development of a highly adaptable movement system may be more beneficial to
improving serve performance than traditional approaches that decompose and accentuate consistency
in the service action. Explicitly, coaches may command varying service performance (speed, spin, location),
scale the court dimensions, or administer stochastic perturbations of the ball toss early in development
to foster the mechanical and/or perceptual proficiency required in the tennis serve."

The study of baseball pitching is useful for understanding the tennis serve because the available research for baseball is considerable. Many of the same muscle stretches and joint motions, particularly the stretch shorten cycle for external shoulder rotation (ESR) and internal shoulder rotation (ISR), are used for both motions. This stretch shorten cycle makes use of the largest muscles attached to the arm, the lat and pec.

(Terms - In many countries, internal shoulder rotation is called medial shoulder rotation.)

The study of baseball pitching is useful for understanding the tennis serve because the available research for baseball is considerable. Many of the same muscle stretches and joint motions, particularly the stretch shorten cycle for external shoulder rotation (ESR) and internal shoulder rotation (ISR), are used for both motions. This stretch shorten cycle makes use of the largest muscles attached to the arm, the lat and pec.

(Terms - In many countries, internal shoulder rotation is called medial shoulder rotation.)

There is a need to understand the difference between the highest level tennis performance and the tennis practiced by lower level tennis players. This publication deals with this comparison in general for certain type sports, golf, in particular, is discussed.
Sample chapter from theRoutledge Handbook of Sports Coaching, 2015
Edited by Paul Potrac, Wade Gilbert and Jim Denison

Performance Factors Related to the Different Tennis Backhand Groundstrokes: A ReviewCyril Genevois,1,✉*Machar Reid,2,*Isabelle Rogowski,1,* and Miguel Crespo3,*Author information ►Article notes ►Copyright and License information ►
This article has been cited by other articles in PMC.Go to:Abstract
The backhand is one of the two basic groundstrokes in tennis and can be played both with one or two hands, with topspin or backspin. Despite its variety of derivatives, the scientific literature describing the backhand groundstroke production has not been reviewed as extensively as with the serve and the forehand. The purpose of this article is to review the research describing the mechanics of one and two-handed backhands, with a critical focus on its application to clinicians and coaches. One hundred and thirty four articles satisfied a key word search (tennis, backhand) in relevant databases and manual search, with only 61 of those articles considered directly relevant to our review. The consensus of this research supports major differences between both the one- and two-handed strokes, chiefly about their respective contributions of trunk rotation and the role of the non-dominant upper extremity. Two-handed backhand strokes rely more on trunk rotation for the generation of racquet velocity, while the one-handed backhands utilize segmental rotations of the upper limb to develop comparable racquet speeds. There remains considerable scope for future research to examine expertise, age and/or gender-related kinematic differences to strengthen the practitioner’s understanding of the key mechanical considerations that may shape the development of proficient backhand strokes.

ABSTRACT
The forehand ranks closely behind the serve in importance in the sport of tennis. Yet, while the serve has been the focus of a litany of research reviews, the literature describing forehand stroke production has not been reviewed as extensively. The purposes of this article are therefore to review the research describing the mechanics of the forehand and then to appraise that research alongside the coach-led development of the stroke. The consensus of this research supports the importance of axial rotation of the pelvis, trunk, shoulder horizontal adduction and internal rotation as the primary contributors to the development of racket speed in the forehand. The relationship between grip style and racket velocity is similarly well established. However, it is also clear that there remains considerable scope for future research to longitudinally examine the inter-relationships between different teaching methodologies, equipment scaling and forehand mechanics.

The stretch-shorten cycle depends on elastic forces that are produced by Titin, a giant protein molecule in the sarcomere.

This very advanced presentation by Walter Herzog discusses Titin and state-of-the-art research. One interesting issue is the effect of activating the Titin to increase the 'passive' force. The forces from Titin can be enhanced depending on 'activation' in a manner similar to that of EMG signals for activating active muscle forces. Both may depend on calcium ions released into the sarcomere. The quality of the stretch shorten cycle is related to this research.

I just viewed the long video. I'm a bit overwhelmed for now and don't have the background to follow much of the presentation. Later will pick a few times with some information that I think is interesting and might relate to the stretch shorten cycle on tennis strokes.

I will update with additional references on 'active stretch" as I find.

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Tennis publications such as the book the Biomechanics of Advanced Tennis referred to activating stretched muscles before using them in the stretch shorten cycle. They referenced the publication below.

This simple experiment involves research into muscle activation ('active' nerve instructions) to stretched or stretching muscles just before those muscles shorten. There is a force enhancement (increase) to the muscle contraction when this is done. It was identified in the Biomechanics of Advanced Tennis as part of tennis strokes, page 33.

I have this on my desk as the bible of tennis bodies and motion. Well done guide.

Sent from my iPhone using Tapatalk

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I have this book also. It is specific to tennis, illustrations for each stroke identifying muscles, an excellent book.

I use The Manual of Structural Kinesiology, Thompson & Floyd, a few times each week. It discusses each muscle and joint motion with clear illustrations. It lists the various joint motions that each muscle can do, options. For example, if your stretch ISR muscles in the ESR-ISR stretch shorten cycle, so important for the serve, you know from the book that each of these stretched muscles involved can also do other joint motions in addition to ISR. The lat, for example, can do ISR or extension or adduction and combinations of these joint motions. The lat can also move the upper arm forward by shoulder extension in the serve and probably is doing so. The book is a popular college text in about its 20th+ edition. The 15th edition (2004) probably costs under $10 used. With Tennis Anatomy to identify the main muscles for strokes and this book for muscle & joint detail, you cover a great deal of the motions that you encounter.

I have this book. It is specific to tennis, illustrations for each stroke identifying muscles, an excellent book.

I use The Manual of Structural Kinesiology, Thompson & Floyd, a few times each week. It discusses each muscle and joint motion with clear illustrations. It lists the various joint motions that each muscle can do, options. For example, if your stretch ISR muscles in the ESR-ISR stretch shorten cycle, so important for the serve, you know from the book that each of these stretched muscles involved can also do other joint motions in addition to ISR. The lat, for example, can do ISR or extension or adduction and combinations of these joint motions. The upper arm also moves forward for shoulder extension in the serve. The book is a popular college text in about its 20th+ edition. The 15th edition (2004) probably costs under $10 used. With Tennis Anatomy to identify the main muscles for strokes and this book for muscle & joint detail, you cover a great deal of the motions that you encounter.

Click to expand...

This is basic anatomy. If you know the origins and insertions of the muscles you can deduce their actions via the direction of their striations.

Pec major also internally rotates the humerus, adducts the humerus, plays a small role in flexion (clavicular head) and extension (sternal head)...

Teres major is anothe internal rotator. Subscapularis...it's not groundbreaking stuff

Meanwhile there is no perfect range or joint motion. Everybody has their own unique biomechanics based on their individual anatomies. Form follows function, and function follows form. So I know you like to analyze people's form and compare them to this proverbial perfect model, but you have to realize that the form people use may be the perfect form for them

This is basic anatomy. If you know the origins and insertions of the muscles you can deduce their actions via the direction of their striations.

Pec major also internally rotates the humerus, adducts the humerus, plays a small role in flexion (clavicular head) and extension (sternal head)...

Teres major is anothe internal rotator. Subscapularis...it's not groundbreaking stuff

Meanwhile there is no perfect range or joint motion. Everybody has their own unique biomechanics based on their individual anatomies. Form follows function, and function follows form. So I know you like to analyze people's form and compare them to this proverbial perfect model, but you have to realize that the form people use may be the perfect form for them